Electropneumatic brake



Dec. zo, 1927. 1,653,135

T. H. THOMAS ELECTROPNEUMATIC BRAKE Filed Feb. 23. 1927 63 26 44 45|NVENTOR THOMAS HJ'HoMAs BYWM@ ATTORNEY Patented Dec. `20, 1927.

UNITED STATES PxrENT` OFFICE.

THOMAS H. THOMAS, OF`EDGEWOOD, PENNSYLVANIA,` ASSIGNOR TO THE WESTING- HOUSE AIR BRAKE COMPANY, OF PENNSYLVANIA.

OF WILMERDING, PENNSYLVANIA, A CORPORATION ELECTROPNEUMATIC BRAKE."

Application l'ed v}. "ebruary 23, 1927. Serial No. 170,074.

This invent-ion `relates to electro-pneumatic brakes and more `particularly to( a brake equipment for electrically controlling the brakes on a locomotive and cars in a train. f

The principal object kof my invention is `to provide an improved electro-pneumatic pneumatic brake equipment employed on the locomotive and each car in the train.

As shown in Fig. 1 in the drawing, the locomotive is equipped with a brake switch 1 and Aa combined alternating `and ,direct current generator 2, While both the locomotive and cars are provided with a magnet valve device 3, La magnet valvev device 4 and two rectifiers 5 and 6.` The magnet valve devices 3 and 4 are associated with the electro-pneumatic apparatus 7 as shown `in Fig. 2 of the drawing, in addition to the usual auxiliary reservoir 8 and brake cylinder 9.

The brake switch 1,fshown in development form on the locomotive` in Fig. 1, may com prise a contact drum, adapted to be operated by a handle; the rotation of said drum being adapted to effect the electrical connections in t-he various positions of the brake switch.

The generator 2 may be of such eonstruction as to produce both alternating and divect current, the `current from which is adapted to be controlled `through the connections of the brake switch 1 :for controlling the application and the release of thebiakes` The magnet valve device 3 comprises a magnet and is providedy with a chamber `1() containing avalve 11, said valve-having a fluted stem extending th-rough a suitable bore in the casing and engaging in a chamber 12 the tluted stem of .awvalve 13 contained in chamber 14. The valves 11 and 13 are adapted to `be shifted in one direction by operation of the magnet, and when said magnet is deenergized, the pressure of spring 15 againstl the .collared stem' `16 l1n vvalve having `a l'lutedV stem engagement, with the valve 13, Ashifts the valves in the opposite direction.l

The magnet valve device 4 comprises a magnet adapted to operate a double beat valve 17 contained in chamber 18, the lower extending through a bore in the casing and engaging the collar of a stem 19, engaged by a spring y2O contained` in chamber 21. The fluted stem of the upper valve extendsthrough a chamber 2 2, connected to the atmosphere through the exhaust passage 23.

The rectifier device 5, is interposed in the circuit from train wire 24 to'magnet 3, and is kadapted to permit the flow of current only inv one direction, such as indicated by :the

arrow. i n

The rectifier device 6 isinterposed in the circuit from the train wire 24 and to the magnet 4,y and is adapted to permit the flow of current only in one direct-ion, such as indicated by the arrow, the direction of flow being opposite to that permitted ,by the rectifier device 5.

The single train wire 24 is continuous throughout the train, being connected between cars and the locomotive by a suitable flexible connection `or., jumper 25 and is grounded at the end of the train as shown v at 26.

The electro-pneumatic valve equipment- L7 is similar` to that disclosed in -my prior Patent, N o. 1,440,421, granted January 2, 1923, and may comprise a quick action triple valve device 27, and a selector valve portion 28, both of `which are mounted on a bracket 29,r to which the auxiliary reservoir 8 and p brake cylinder 9 are also connected. The quick action triple valve device 27,

comprises a casing havinga piston chamber 30, connected to the usual brake pipe 31, and containing a piston. 32 anda valve chamber 33, connected through passage 34 to the 'auxiliary reservoir 8, and containing 'a main slide valve 35 and an auxiliary slide Valve 36, adapted to be operated by said piston.

The quick action `portion ofthe vtriple valve device comprises the usualquick action pistonl 37, contained in chamber 38, and the vent valve 39, .contained in chamber 40,`a'nd adapted to be operated by said piston. The usual check valve 41 is also contained in chamber 40. l

The selector valve portion 28 comprises a casing having a piston chamber 42 connected through passage 43 with chamber 18r of the magnet valve device 4, and containing a piston 44 subject to the pressure of a coil spring 45 and a valve chamber 46 connected to the triple valve chamber 83 through passages 47 and 48 and containing a slide valve 4S), adapted to be operated by said piston. The magnetI valve device 3 and magnet valve device4 are mounted on a bracket integral with the selector portion casing 28.

The brake switch 1 is separate trom the usual automatic brake valve device (not shown) and is adapted to be operated independently, while the automatic brake valve device remains in the usual running position.

In operation, the 'fluid pressure brake system is charged in the usual manner and iiuid from ther brake pipe 81 flows to the piston chamber ot the triple valve device 27 and thence through feed groove 5() to the valve chamber 88 andthrouglrpassage 34 to the auxiliary reservoir `8 charging said reservoir in the usual manner.

Fluid under pressure is supplied from the valve chamber 38, througli'passages 48 and 47, to the selector valve chamber and from passage 47 through passage 51 to the spring'chambers 14 and'21.

`With the brake switch 1in running position, as shown in Figure 1ct' the drawing, the train wire 24 is connected to the positive pole 52 of the directv current winding of the generatorf2, by way ot' switch contact 53 and wire 54. The circuit `is then completed through the negative pole of the genera tor 2r` the `wire 56,'drumcontact 57, wire 58, and ground 59, the train vwire 24 being connected at 2G tothe ground at the end o'l the train. i E

lhenthe positive pole of the direct current winding ot the generator is connected tothe train wire,current .flows through the rectifiersA 5 and magnets 3, but the rectitiers 6 prevent the flow otl current in this direction to the magnets 4. Thus the magnets 3 become energized while the magnets 4 remain deenergized.

The magnet 4 being deenergi'zed, the double beat valve 17 is seated in itsupper position, which permits the low ot auxiliary reservoir fluidfrom spring chamber 2l into valve chamber 18 and thence Ythrough passage 43 to the piston chamber 42 ofthe selector valve. The Huid pressures thus equalizeon the opposite sides ot the selector piston 44 and the pressure ot' the spring 45 holds said piston and slidevalve 49 in the upward orrelease position.

`The magnet 3 being energized seats the valve 11 and unseats 'the valve 13.` which permits `the fluid at auxiliary reservoir pressure in spring chamber 14 to iiow to chamber 12 and thence through passage 60 and pipe 61 to thereservoir 62, charging said, reservoir. Passage G0 also lea-ds to the seat ot the selector slide valve 49, but it is lapped by the slide valve in release position.

With the triple valve and selector portion both in release position, the brake cylinder 9 is connected to the atmosphere through passages (31, 62, and 8G, past the ball check valve 63, passage 64, cavity in the triple valve slide valve 35, passage 66, cavity 67 in the selector slidewalve 49 and the atmospheric exhaust port G8. Y

It it is desired to el'lectl a service application of the brakes, the brake switch- 1 is turned to service position, in which a circuit iscompleted from the ground 26 through the train wire 24, contact G9 `of the brake switch, wire 70, contact 71, and wire 56 to the negative pole 55 of the generator direct current winding, through the direct current winding of the generator to the positive pole 52 of the generator, and thence through the wire 54, contact 72, wire 58 to ground 59.`

lith 'the negative pole 55 of the direc-t vcurrent winding of the generator 2 connected to the train wire 24, current tlows through.

the magnets 4 and rectifiers G in the 'opposite i direction from `that in runningposition, so 'that the rectitiers 5 prevent the flow of currentin this direction,l and consequently the magnets 3 are deenergized, 'while the magnets4are`energized.

Energization of the magnet 4 seats the double beatvalve 17 in its lower position and closes communication between chambers 21 and 18 and connects chamber 18 to chamber 22. Fluid under pressure 'from the selector valve pistonchamber 42 is then vented to the' atmosphere through passage 43, double heat va'lvefchamber 18, :and chamber 22 to the ffatn'ioslrihericexhaust passage 28, which permits the tiuid pressure in valveV chamber 46 to 'shifttheselcctor `valve piston 44 and slide valve 49 downward to service position, against the pressure ot spring 45. In' service position, the brake cylinder passage `66 is lapped b v the slidevalve 4S) and passage GO is uncovered, so that valve chamber 46 is connected to passage (S0.

The magnet 3 being (leenergized", the valve 13 is's'eated and the valve l1 unseatcd,

which permitsfluid'under pressure from the auxiliary reservoir t8 to be vented to the brake cylinder through passages 48 and 47, selector valve chamber 4G, passage ('30,` cha1nber12 in the magnet valve device 8, past the valve 11, thence through 'passage 73,k past the ball checkj valve 74, through passage 75, cavity 7 6 in the selector' y,slide valve 49,1passages 77, 64,` 62, and 6l to thebrakecylinder9. I t

If itis desired to limit the degree of brake cylinder pressure and therefore of the "brake application, the brake switch is moved to lap position in which a circuit is completed through the train wire 24, Contact 78 the brake switch, thence through wire 7 9, contact 80, wire 81, the alternating current winding of the generator 2 and through Wire 82 to the locomotive ground, S3,y the train wire being grounded at 26 at the end of the train. l

The alterna-ting current `then supplied to the train Wire 24 passes through both rectiiiers and 6 and magnets 3 and 4, thereby energizing both magnets.` f j The magnet 4 being energized in lap position of the brake switch kmaintains the double beat valve 17 `and the selector piston and slide 'valve in service position. The magnet 3 being deenergized, the valve 13 is unseated and the valve 11 seatedso that further flow of fluid under pressure'to "the brake cylinder is prevented.

The brake cylinder pressure may beincreased .in steps as desiredby alternately moving the brake switch between service and lap positions, as will be evident.

The brakes may be` released by moving the brake switch 1 to running position in which the positive pole of the direct current winding of the generator 2 is connected to the train wire 24, thereby causing the magnets 3 to be energized and the magnets 4 to be deenergized, .as hereinbefore. described. n

Deenergization of magnet 4 permits the pressure of spring to shift the'double beat valve 17 to its upper position and permit the flow of fluid under pressure from spring chamber 21 to chamber 12 and thence through passage 43 to the selector piston chamber 42. 49 are then shifted to release position in which the brake cylinder 9 is connected to the atmosphere through the exhaust passage G8.

It' the brake switch 1 is left in running Y position the brakes Will be 'fully released,

but if it is desired to effect a graduated releaseV of the brakes/the brake switch may be moved from running to lap position, in-

which the alternating current is supplied to the train Wire 24 which operates the magnets 3 and 4 to prevent any further change in brake cylinder pressure, the same as in graduating the application. Thus, by altween running and lap positions, the` brake cylinder pressure may be reduced in steps as desired. 4

To effect an emergency application of the brakes, the brakeswitch is moved to emergency position in Which the train Wire circuit is opened, which causes both magnets 3 and 4 to be deenergized.

The deenergization of magnet 4k operates to maintain the selector piston 44 and slide valve in release position. tion of magnet 3 permits the valve 13 to be seated and the valvey l1 to be unseated byy The piston 44 and slide valvep ternately moving the brake switch be- The deenergiza` the pressure of spring 15. Unseating valve llypermits the fluid under pressure inthe normally charged reservoir 62 to flow to the quick action piston 37 ofthe triple valve device, through pipe 61, passage 60, chambers 12 and l0, passage 73, past ball check valve 7 4,'passage 75, cavity 76 in the selector slide valve 49 and through passage 84.

VSaid piston then yoperates to unseat the brake pipe vent valve 39 and vent chamber 40 to the brake cylinder 9.

The fluid under pressure in the brake pipe 31 then lifts the check valve 41f`and `flows'into chamber 40 and thence to the brake cylinder to effect a sudden local reduction in brake pipe pressure in the usual manner.

circuit, that it' the train Wire becomes broken kor they supply of current fails, an

emergency application of the brakes will be automaticallyeffected in the same manner as described above. If a `car `equipped with the above described apparatus is placedin' a train not provided With electric cont-rol, the magnets 3 and 4 will both be deenergized, so ythat the valve 13 will be seated so as to cut oft' the supply of fluid under pressure to the reservoir 62 and said reservoir Will be vented to the brake cylinder through the open valve 11. Since there is no fluid under pressure in the reservoir 62 under the above conditions, there will be no action of the electric portion, and the equipment of the train will operate only pneumat-ically yin the usual manner.

lVhile in making an electric service applicationof the brakes, the auxiliary reservoir pressure tends to be reduced, but the pressure in` said reservoir will be substantially maintained by flow from the brake pipe through feed groove 50, on account of the automatic 'brake valve deviceremaining in running position.

Having now described my invention, what I claim as new and desire to secure by Let# ters Patent, is

1. kIn an electrically controlled'brake, the combination with a single train Wire, of

llO

electrically controlled devicesv connected in parallel With said train Wire for controlling the brakes and rmeans in series with each device for permitting the floW of current` electrically controlled devices connected in parallel with said train wire tor controlling the brakes, means in `series with one device :tor permittingflow of current through said device in one direction only, and means in series with the other device for permitting flow of current through Ysaid device only in the opposite direction-` In an electrically vcontrolled brake, the combination with single train wire, of two electrically controlled devices connected in parallel with said train wire for controlling the brakes, a rectifier in series with one device for preventing flow of current through said device in `one direction and a rectifier in series with the other device for preventing.

trolling the brakes in accordance with the character and direction of flow of current through said train wire. e

5. In an electrically controlled brake, the combination with a single train wire, of electrically controlled means connected to said train wire and operatedupon a flow of direct current through said wire in one/direc- .tion for effectingl the release of the brakes, upon a .flow of direct current through said wire in the reverse direction for effecting an applicationy of the brakes, and upon a flow ot alternating current through `said wire for placing said means in a lap condition and means for supplying direct current to said wire in either direction of flow, or alternating current.

6. In an electrically controlled brake the combination with a single train wire, of generator means for Vsupplying direct current andv alternating current, a brake switch devicek for connecting said generator-.means to said train wire and having one position for supplying direct current flowing in one direction to said train wire, another position for supplying direct current flowing in the reverse direction to said train Wire, and another position for supplying alternating current to said wire, and electrically controlled means connected to said train wire and operated by direct current flowing through said train wire in one direction for releasing the brakes, by direct current flowing through said wire in the opposite direction for applying the brakes, and `by alternating current flowing through said wire for holding the brakes fapplied or released, as` the case may be. y i

In testimony whereof `I have hereunto set my hand. y

THOMAS H. rrnoimis 

